Cool Controls Save Cold Cash

A favorite business management “equation” at work in today’s refrigerated warehouse controls development arena is: less energy use + more information = customer peace of mind.

End-users who manage storage facilities, and service-aware refrigeration contractors continue to ask for controls that are more energy efficient, enable other systems to operate at reduced energy levels, and provide enhanced reporting capabilities for record keeping and troubleshooting.

Energy conservation is a primary concern. Wasted energy service dollars speak volumes, and manufacturers of sophisticated controls products are listening to concerned customers and contractors, and are designing more innovative products sooner rather than later.

“The second need is to be able to maintain food quality more dependably, and provide alarm capabilities. This relates to tight temperature control, and the ability to quickly notify the customer or contractor of a rise in temperature,” Guzowski explains.

“As energy costs are rising, the market is demanding equipment that is more efficient, which means that equipment is always evolving,” agrees Pat Melvin, engineering manager for Master-Bilt, New Albany, MS, manufacturers of refrigerated cases, coolers, freezers, and digital alarm and light management systems.

“Technology is changing fast, and it’s mostly energy-related; so as a manufacturer, it’s our job to meet those energy expectations, and at the same time to keep it simple,” Melvin says. “It’s our goal to put equipment in front of contractors that’s very similar to what they’ve seen in the past, and to keep the installation and setup as simple as possible.”

“If we install a control system that tells us when to perform routine maintenance, and thereby avoid a failure, or helps us avoid unplanned maintenance, we’re dollars ahead of the game in our maintenance budget, and operationally, in terms of the amount of electricity our customers use,” says Bill Almquist, president of Almcoe Refrigeration Company, Dallas, TX, a 47-year-old refrigeration company that designs, sells, installs, and services refrigeration systems for cold storage facilities, restaurants, grocery stores and convenience stores.

“Information is one of the most powerful tools we have,” says Almquist. “The control systems we’re installing today allow us to better monitor all those things that are critical to reducing energy and anticipating scheduled maintenance.”

More Dependable Reporting In these times of intense federal scrutiny over food quality, detailed reporting and temperature trending are key features in modern refrigerated warehouse controls.

ProAct is an Internet-enabled service that records and manages the documentation supermarkets need to maintain compliance with Section 608 of the Environmental Protection Agency’s (EPA) Clean Air Act. The service provides electronic access to all refrigerant data for management, analysis and reporting purposes, and alleviates many of the hassles and omissions associated with paper tracking.

“Most of these warehouses run three, 8- hour shifts, and they’ll ask us to automate the reporting, which we can do via Emerson’s auto poll reporting service,” Guzowski says.

“We can customize the system to generate reports at the end of each shift, and the control equipment can survey the temperatures of the different warehouse areas. We can store that data for the customer’s archives, export it into a file, or print a report. We provide an intuitive, graphical PC interface to our control system, so the servicing contractor can go to the PC and do an overview of all the equipment,” Guzowski says.

“Emerson developed a comprehensive graphics package to summarize a variety of data, such as ‘evaporator temperatures as compared to set point.’ Contractors can determine if anything is in an alarm mode, or trend a graph by pulling two or three weeks of data. They can also review the status of the condensing units, run time, if any are in alarm mode, suction pressure and discharge pressure, or if they’re getting any trips or failures. This service gives the contractor one more benefit to offer to the customer.”

‘Alarming’ Developments Sophisticated alarms — standard in many newer controls — are attuned to just about every possible system failure, and are designed to get the attention of those in charge.

“We can provide an audible local alarm, such as a horn sounding, or a strobe light that’s activated locally to notify operations people,” Guzowski explains.

“Or, you can get more sophisticated, and send the alarm to a cell phone, PC, pager, or fax machine. That’s very desirable for service contractors who are not on-site, especially if they have a maintenance contract, and are liable for keeping the equipment operating.”

Going ‘Back in Time’ As a service contractor, Bill Almquist prizes historical data as a way to diagnose cooling system problems. He’s especially pleased with Emerson’s E2 controller. Version 2.5 of the E2 RX contains new algorithms that Emerson says improve refrigeration system performance for supermarket operators by reducing compressor cycling and making compressor asset and performance information available to users. As part of Emerson’s Intelligent Store architecture, the E2 RX optimally manages low and medium temperature systems, and manages and monitors the refrigeration racks and/or condensing units that contain compressors and valves necessary for proper system operation.

The new algorithms in the E2 RX reduce compressor cycling, which is a major cause of decreased equipment life and possibly excessive energy consumption.

“I find Emerson’s E2 to be the best of the recent control products available,” says Almquist. “Emerson has designed it to be easy to understand, navigate, install, and commission.”

“If a customer tells us the cases tend to become warmer at 2 o’clock in the afternoon, and they were working fine at 8:00 in the morning, we access the E2 and review temperature recordings from the past 24 to 48 hours, in 10-minute samplings; we take pressure recordings, recordings of refrigerant levels, head pressure, suction pressure, temperature, and determine which compressors are running.”

In essence, Almquist says, the E2 allows him to ‘go back in time’ and review conditions related to the time of day the discrepancy occurred.

Bill Way, manager of automation and special products for Hughes Environmental Engineering, Montvale, NJ, is currently involved with installing a Johnson Controls Tridium system — a microprocessor-based unitary controller with webaccess interface — at a large cheese importer.

“The biggest demand now relates to trending,” Way says. “The FDA and others are getting tougher on food producers’ ability to track and prove temperature maintenance. This includes controlling, trending, and scheduling. There’s also a lot of demand limiting, to save money.”

Way appreciates the accuracy and comprehensiveness of today’s sophisticated controls.

“The most improvements have been in trending and access capabilities,” Way says. “Today, we can control everything related to a facility, including the evaporator fans, defrost, and the compressor stop/start; some are even controlling lighting, and shutting off fans when the building isn’t occupied.”

And, even though the contractor is the recognized expert, Way says customers still wamt to know what’s going on at their facitlities at any given time, and have come to appreciate the ‘round-the-clock access to building information that is now possible by using web server technology.

“It allows them access to their buildings from anywhere they have Internet availability, and saves the expense of special software and having to lug a laptop around with them,” Way says.

Warehouse controls account for about 80% of Logic’s design and installation business. It services industry heavyweights such as Wal-Mart, SYSCO Foods, Publix, and Kroger.

On two current projects, Logic is installing new variable frequency drives (VFDs), to operate the fans and evaporators at slower speeds, for improved energy management.

“VFD technology has made tremendous strides,” says Simpson. “Ten to 15 years ago, these types of VFDs were very cost-prohibitive for fan controls, with a payback of about 10 years. Now, the payback is a year and a half, or two years. Some of these plants have a $150,000 electric bill each month. Shaving 10 to 20% off of electricity costs by using these technologies can pay back an entire control environment in one year, in some cases.”

Huge strides in wireless technology have greatly improved the flexibility of system monitoring. “You can walk around the plant with a PDA, to obtain readings and control equipment, or, you can operate a valve group right on the spot, instead of having to radio back-and-forth with someone in a control room in order to make something happen on the roof,” Simpson says.

“Sensors are much more efficient and affordable, so that you may now put many more sensors in a plant to find warm spots,” Simpson says. “Today, you pay only $60,000 for sensors that would have cost half a million dollars 30 years ago. Overall, the entire PC environment has reduced the cost of computing, and that’s spilled over into the industrial market. That includes the VFDs, microprocessors, PCs, and sensing devices,” he says.

More to Come Stay tuned for further developments, viewers, because controls manufacturers are moving forward at a brisk pace to keep in step with market growth.

“Our strong economy is producing new food processing and storage facilities, and people are recognizing the need to replace outdated equipment with newer, more reliable, more efficient equipment,” says Master-Bilt’s Pat Melvin.

Looking forward then, contractors can expect “more of the same,” which is a good thing, because, to state one more business equation: more research and development + improved controls = happier contractors and customers.

It’s just basic math.

Emerson, Zero Zone Develop Condensing Units Emerson Climate Technologies, a business of Emerson, St. Louis, MO, and Zero Zone, Inc., North Prairie, WI, have co-developed a new line of precharged condensing units for Zero Zone’s Hybrid™ reach-in cases for medium- and low-temperature applications.

The product line was specifically designed to help retailers avoid complicated refrigeration rack and piping installations, a benefit which Zero Zone calls “refrigeration without complication.”

The cases blend the merchandising power of a supermarket case with the ease and flexibility of a self-contained unit. They offer compact size, simple connections, and field-installed, top-mounted condensing units, designed to provide fast, easy installation.

According to Danfoss, reciprocating compressors are more efficient at low evaporating temperatures than other technical compressor platforms.

The new motor design is optimized for low temperature operation, which reduces energy consumption, while increasing compressor efficiency. Additional liquid injection to cool down the compressor is unnecessary, because they’re 100% suction gas-cooled, and rapid chilling.

The NTZ series has an extended evaporating temperature range from -10C to -45C, allowing versatility over a wide range of low temperature applications.

The motor also features improved electrical characteristics, such as lower LRA (locked rotor current) and MCC (maximum continuous current), which allows for the selection of smaller safety devices.

Heatcraft says the new motors — which can be used in supermarkets, restaurants, convenience stores, warehouses, unit coolers, wineries, and other applications — bring the abovementioned unit coolers into compliance with California CEC Title 20.

The motors are another of Heatcraft’s Energy Solutions options, developed to reduce energy costs and improve unit cooler performance.

According to the company, EC motors are up to 85% efficient, with test data showing a 51-60% increase over shaded pole motors and a 30-40% increase over permanentsplit capacitor (PSC) motors.

EC motors are also available as an InterLink aftermarket part. As a drop-in replacement for existing shaded pole and PSC motors, Heatcraft says contractors will find they’re easy to install, and can help customers reduce energy costs without replacing an entire system.